Survivorship among young Alpine marmots and their permanence in their natal territory in a high altitude colony

Abstract

During an eight year study on the ethology and ecology of the alpine marmot (Marmota marmota L.), carried out in the Gran Paradiso National Park, Aosta, Italy, 41 young marmots were individually recognized and data on birth rate, litter size, permanence beyond maturity, and productivity were recorded. Litter size had a median of four (range 4-5). No female had a litter in the first year of settling and all females but one had a one year interval in reproduction. 36.6%; 34.1%; 21.5% and 0 animals born in the colony were found in the natal territory when one, two, three and four years old, respectively. The differences found in comparison to other geographical areas might be related to the high turnover rate of social groups and indirectly to the harshness of the habitat where the study area is located.